Alcohol-ammonia dye solution and dyeing therewith

ABSTRACT

A dye system in which materials are bathed in a dyebath formed of a dye dissolved in a substantially anhydrous liquid ammonia. A mono-hydroxy lower alkyl alcohol is added as a leveling agent and to improve hand.

United States Patent Prieto Apr. 9, 1974 ALCOHOL-AMMONIA DYE SOLUTION[56] References Cited AND DYEING THEREWITH UNITED STATES PATENTS [75]Inventor: Humberto Prieto, Gastonia, NC. 3,666,398 5/1972 Tramyek 8/82[73] Asstgnee: 2232522 3 2 Mills? Primary Examiner-Donald Levy Attorney,Agent, or FirmSchiller & Pandiscio [22] Filed: Aug. 3, 19 72 I 211 App].No.2 277,771 [571 ABSTRACT A dye system in which materials are bathed ina dyebath formed of a dye dissolved in a substantially anhy- [52] U5. Cl88//l8 A,88/g337,88//l4743, drous liquid ammonia A mono hydroxy loweralkyl [51] Int Cl DMD D06p U38 alcohol is added as a leveling agent andto improve I hand Field of Search .Q 8/82 173, 37, 44, l A

18 Claims, No Drawings ALCOHOL-AMMONIA DYE SOLUTION AND DYEING THEREWITHThis invention relates to systems of dyeing or coloring materials andmore particularly to new methods of dyeing materials such asproteinaceous, cellulosic and synthetic fibers and sheets.

Dyes are usually applied to fibrous material from aqueous solution, andgenerally require imbibition periods of many minutes even with heatedsolutions. Ad-

ditionally, various dyes capable of dyeing one type of fiber in aqueoussolution are ineffective for other types of fiber. A usualclassification of dyestuffs is according to their use, and typicallywill include direct, disperse, naphthol, reactive and sulfur dyes.

' Direct dyes are water-soluble dyes that exhaust onto cellulosic fibersfrom a salt bath without mordanting. Chemically nearly all direct dyesare azo products with one or more sulfonic radicals, and most contain aplurality of the azo groups. They are used on cotton, rayon, silk andwool but are not ordinarily considered suitable for dyeing celluloseacetate.

Disperse dyes are colored organic dyes that although relativelyinsoluble can be dispersed in water in particulate form. These dyestypically are not useful on cotton or viscose rayon, but the particleshave an affinity for and thus dye cellulose acetate well.

Naphthol dyes are water-insoluble azo dyes usually formed on or in afiber by a two-step process in which a diazotized organic amine iscombined in aqueous solution with naphthol previously impregnated intothe textile material. These are primarily used to dye cotton, rayon,silk and nylon.

Dyes with chemically reactive groups which can react with a substratematerial to bind themselves chemically to the substrate are known asreactive dyes. Usually, special conditions or operations are required touse such dyes.

Sulfur dyes are normally insoluble substances brought into water-solubleform for dyeing by treatment with hot alkali solution containing Na s.These are generally used for coloring cotton and, to a limited extent,on silk and rayon because the hand of the latter is adversely affected.Because of severe damage from the alkaline sulfur bath, these dyes arenot used on wool.

The usual dyeing systems and the types of fibers for which a dye isparticularly useful have heretofore been largely limited to dyeing fromaqueous solution. While dyeing from aqueous solution systems may providereaorganic solvents currently used may be undesirable from a standpointof safety, and produce poisonou sonably satisfactory dyeings from astandpoint of color tone and dye levelness, such systems have thedisadvantage in usually requiring relatively long imbibition times,e.g., typically from about 30 minutes-l0 hours or more. As a result, thedye vats, etc., must be relatively large thus increasing capitalinvestment. Furthermore, such systems normally require relatively highdyebath temperatures which may often approach the boiling point ofwater. Such increases utility costs of operating the system. Anadditional disadvantage of aqueous systems is pollution from disposal ofspent dyeing solutions.

in a few limited instances, dyes had been applied from organic solventssystems such as alcohols or aromatics and the like. However, suchsystems may require solvent recovery both from an economic standpointand to avoid pollution. Furthermore, some of the gases or may beflammable.

One current system of dyeing involves dyeing from liquid ammoniasolution according to the method disclosed by Tratnyek, U.S. Pat. No.3,666,398. With this method imbibition time is radically less ascompared to dyeing from aqueous systems. Also, in this method dyeing isaccomplished at low temperatures, and does not involve the use of costlysolvent. On the other hand, in

the Tratnyek method dyeings may occasionally be unlevel and coarsen thefiber. The unlevelness is believed to be attributed at least in part tothe very high speed at which dyeing occurs in the liquid ammoniadyebath. In any event, whatever the cause of the unlevelness, it poses aproblem in the commercial exploitation of the Tratnyek method except incases where dye levelness is not required.

It is thus a primary object of the present invention to provide a noveldyebath for dyeing substrate materials. Another object of the inventionis to provide a novel method of leveling dyeings with dyestuffs appliedfrom liquid ammonia solution. A more specific object is to provide anovel method of improving the levelness of dyeings made according to theTratnyek U.S. Pat. No. 3,666,389 and to improve the hand of fabric sodyed.

To effect the foregoing and other objects, the present inventiongenerally contemplates the use of a monohydroxy lower alkyl alcohol in adye system comprising a dyestuff dissolved in substantially anhydrousliquid ammonia.

Other objects of the invention will in part be obvious and will in partappear hereinafter. The invention accordingly comprises the processesinvolving the several steps and the relation of one or more of suchsteps with respect to each of the others, and the products possessingthe features, properties and relation of elements which are allexemplified in the following detailed disclosure and the scope of theapplication of which will be indicated in the claims.

In the following detailed description of the present invention, the termliquid ammonia refers to aminonia (NI-l in itsliquid state, i.e., whichboils at about -33,.4C. at 760 Hg. pressure, and not to a solution ofammonium hydroxide. However, it will be appreciated that water can bemixed with liquid ammonia in surprisingly large amounts without thewater becoming frozen. Even when approximately equal quantities ofliquid ammonia and water are mixed, there remains an appreciablequantity of the liquid ammonia in the mixture so long as the mixture ismaintained at equilibrium conditions below the boiling point of theliquid ammoma.

As used herein the term mono-hydroxy lower alkyl alcohol refers toaliphatic alcohols having from one to three carbon atoms, i.e.,methanol, ethanol, and the propanols (n-propanol and iso-propanol).

Generally, a mixture of liquid ammonia and the mono-hydroxy lower alkylalcohol isprepared by adding the alcohol to liquid ammonia, preferablyin the proportion of from about 17 to percent by volume of alcohol toammonia. The alcohol preferably is chilled prior to addition of theliquid ammonia mixing so as to minimize loss of liquid ammonia byvaporization.

Thereafter, a dyestuff is dissolved in the liquid ammonia-alcoholmixture to form a dyebath. Alternatively, at least a part of thedyestuff may be dissolved in the liquid ammonia prior to admixture withthe alcohol, and the remainder of the dyestuff, if any, is subsequentlydissolved in the liquid ammonia-alcohol mixture. Another procedure is todissolveat least a part of the dyestuff in the alcohol, and admixingwith the liquid ammonia, and the remainder of the dyestuff, if any, issubsequently dissolved in the liquid ammonia. The latter procedure canobviously only be used with dyestuffs which are soluble in the selectedalcohol.

The usable dyes include those dyes which are soluble in liquid ammonia,such as direct, disperse, napthol, reactive, and sulfur types. Vat'dyesdo not appear to be soluble in liquid ammonia, hence, are consideredamong the substances not included in the invention. The dyebaths of thepresent invention are effective for dyeing a wide range of materials towhich they are applied, for example, cotton, silk, wool, viscose, rayon,acetate, triacetate, acrylic, modacrylic, nylon, polyester, and othernatural and synthetic materials. As is now known, certain materials thatare not considered dyeable by a particular dye in aqueous or organicsolvents, unexpectedly proved to be quite dyeable by that dye in aliquid ammonia dye bath and are equally dyeable in a liquidammonia-mono-hydroxy lower alkyl alcohol dyebath. For example, directdyes and reactive dyes, in liquid ammonia, with or without alcohol colortriacetate deeply'. Further, in both liquid and ammonia and liquidammonia-alcohol dye baths, dyeing is generally completed in about 20seconds or less, although application of the same dye with conventionalaqueous systems employs much longer imbibition times and much higherdyebath temperatures.

The depth of shade achieved in the present invention as in the use ofliquid ammonia dye baths appears to de pend primarily on theconcentration of the dyestuff in the liquid ammonia-mono-hydroxy loweralkyl alcohol solution, and not on dwell time of the fibers in thedyebath. Imbibition periods greater than about 20 seconds do notnormally materially improve coloration.

That the addition of the mono-hydroxy lower alkyl alcohol to thedyestuff-liquid ammonia systems of Tratnyek is responsible for theunique consequences achieved is quite clear inasmuch as dyebathsprepared from the same dye dissolved in'substantially anhydrous liquidammonia by itself, or the alcohol by itself (i.e., with dyestuffs whichare soluble in the alcohol), failed to provide comparable results.

The following examples, illustrative of the principles of the presentinvention, are based upon application of a bath of a dyestuff dissolvedin substantially anhydrous liquid ammonia containing a mono-hydroxylower alkyl alcohol, to a number of different materials as follows: (1)bleached 80 X 80 cotton print cloth; (2) bleached mercerized 80 X 80cotton print cloth; (3) spun viscose rayon print cloth (high wetmodulus); (4) spun triacetate cloth and (5) a multifiber test fabricconsisting of cloth bands of the following sequence of fibers identifiedgenerically, and in some instances by trade name: dull acetate; acrylic(Acrilan 1956); triacetate (Arnel dull); raw cotton; acrylic (Creslan61), polyester (Dacron 54); polyester (Dacron 64); nylon (nylon 60);acrylic (Orlon 75); silk; modacrylic (Verel A); viscose; and wool. r

Generally in the following examples, in order to compare the levelingeffect of adding a mono-hydroxy lower alkyl alcohol to a liquid ammoniabath, each dye was applied to fabric by two different methods: from aliquid ammonia bath, and from a liquid ammonia bath containing amono-hydroxy lower alkyl alcohol. Both the liquid ammonia and the liquidammonia-monohydroxy lower alkyl alcohol solution were substantiallyanhydrous. Dye concentrations in the solutions were as indicated with atotal fabric-to-liquor ratio of about 20 to l in all cases.

The basic procedure was to submerge all swatches of fabric in the dyesolution for 20 seconds for ammonia or ammonia-alcohol dyeings. Excessammonia and alcohol was allowed to evaporate from the treated fabrics atroom temperature (about 20C) before drying in an oven at 120130C forabout 1 to 2 minutes. The dyed fabrics were then usually rinsed orwashed in warm water. Rinsing the fabrics was continued until excess dyewas removed from the fabrics or until rinse water showed little or nocoloring. The fabrics were then dried by ironing.

EXAMPLE I Dye: Sirius Red F3B (Bayer) (C.I. N. 35780) (C.l. Direct Redv) 7 The Colour Index describes thisdye as an polyazo type used fordyeing cotton, silk and'wool. It may also be used for direct printing onthese fibers.

Anhydrous ammonia application Prepare the dyebath by dissolving 2 gms.of dye in ml. anhydrous ammonia.

Saturate the fabrics (1 1.0 gms. total) in the dyebath for 20 seconds.Remove fabrics from dyebath and allow excess ammonia to evaporate at20C. Finish drying at l35C for about 2 minutes. Rinse in. warm water andiron dry as above.

Anhydrous ammonia alcohol application 10 percent solution of isopropanolin ammonia is prepared by slowly adding liquid anhydrous ammonia (42C)to 100 ml. anhydrous isopropanol (0C) to make 1,000 ml. solution. Theresulting solution is observed to be colorless. No separation of alcoholand ammonia is observed. Temperature of solution---37C.

Prepare dyebathby dissolving 2 gms. of dye in 100 ml. of theammonia-alcohol mixture.

Saturate the fabrics (12.1 gms. total) in the dyebath for about 20seconds. Remove fabrics from dyebath and dry the fabrics at 20C toremove excess ammonia and alcohol before final drying at C. for about 2minutes. Rinse as before and iron dry.

Application of dyestuff from anhydrous ammonia and from ammonia-alcoholmixture produce intense coloration of dull acetate, triacetate, viscoseand silk. Cottons are dyed in a lighter shade. The dyeing of cottons andrayons with this technique does not produce as deep a coloration as thatobtained in conventional dyeing. However, triacetate which is uncoloredby the conventional technique, can be highly colored using the anhydrousammonia dyebath. Unleveled dyeing is observed on many of the'fabricsdyed from ammonia only. Dye levelness is particularly poor on thecottons and rayons.

Dye levelness on dyeings from the ammonia-alcohol mixture is comparableto dyeings made by the conventional aqueous techniques.

EXAMPLE u The purpose of this example is to see if dyeing levelnessvaries with the ratio of alcohol-to-ammonia.

Following the procedure described in Example 1, mixtures are prepared ofthe following amounts of isopropanol in substantially anhydrous liquidammonia (all percentages by volume percent):

A. 1 percent isopropanol in liquid ammonia;

B. 2 percent isopropanol in liquid ammonia;

C. 5 percent isopropanol in liquid ammonia;

D. 30 percent isopropanol in liquid ammonia;

E. 50 percent isopropanol in liquid ammonia.

Swatches of fabric dyed from ammonia, and from the ammonia-alcoholmixture are compared for hand. The fabrics dyed from the ammonia-alcoholmixture will be found to have improved hand over the fabrics dyed fromammonia only.

In each case the alcohol and the liquid ammonia appear to be completelymiscible with each other and no separation is observed.

Prepare dyebaths by dissolving gram portions of Direct Red 80 dye insolutions A E.

Saturate samples of the fabrics in the dyebaths for about 20 seconds.Remove the fabrics from the dyebath and dry the fabrics at 20C to removeexcess solvent before final drying at 135C for about 2 minutes. Rinseand wash with detergent as before. Iron dry.

Results By comparing swatches with those obtained in Example I, one seesthat the presence of various amounts of isopropanol in the liquidammonia solvent appears to improve dyeing levelness and hand as comparedwith dyeings made by application from liquid ammonia only. Increasingthe amount of isopropanol up to about percent by volume does appear toincrease levelness. Beyond 10 percent by volume little difference isseen in dyeing levelness.

EXAMPLE III The purpose of this Example is to see if other alcohols willimprove dyeing levelness and hand of dyeings from liquid ammonia.

Following the procedure described in Example 1, mixtures are preparedwith 10 percent volume amounts of the following alcohols insubstantially anhydrous liquid ammonia:

A. 10 percent methanol in liquid ammonia;

B. 10 percent ethanol in liquid ammonia;

C. 10 percent n-propanol in liquid ammonia;

D. 10 percent rn-butanol in liquid ammonia;

E. 10 percent sec-butanol in liquid ammonia;

F. 10 percent tert-butanol in liquid ammonia;

G. 10 percent benzyl alcohol in liquid ammonia.

In the case of methanol, ethanol, and'n-propanol, the alcohol and theliquid ammonia appeared to be completely miscible with each other and noseparation was observed. There is a slight amount of sizzling observedwhen the liquid ammonia is added to the methanol and to the ethanol.

In the case of the butanols, a slight degree of separation can be notedin some instances. With-benzyl alcohol, two discrete layers areobserved,'indicating little or no solubility of benzyl alcohol andliquid ammonia in each other.

Prepare dyebaths by dissolving 2 gramportion-of Direct Red 80 dye in 100ml each of mixtures A G. Dye appears to be fully dissolved homogeneouslythroughout mixtures A F. Dye appears to dissolve only in the largerlayer, i.e., in the liquid ammonia of mixture G.

Saturate samples of the fabrics in the dyebaths for about seconds.Remove sample of the fabrics from the dyebaths and ammonia and alcoholbefore final drying at 135C for about 2 minutes. Rinse and wash withdetergent as before. Iron dry.

Results By comparing swatches with those obtained in Example I, one seesthat dyeings made with solutions A C have substantially improvedlevelness over the dyeing applications from liquid ammonia only. Dyeingsmade with solution mixtures D F have slightly improved levelnesscomparable to dyeing applications from liquid ammonia only, and dyeingsfrom mixture G is substantially as unlevel as dyeings from liquidammonia'only. Hand improves with dyeings from mixtures A C as comparedwith dyeings from liquid ammonia only.

EXAMPLE IV The purpose of this example is to see if addition of a glycolwill improve hand and levelness of dyeings from anhydrous liquidammonia.

Following the procedures described in Example I, mixtures are preparedwith the following amounts of ethylene glycol in anhydrous liquidammonia (all percentages by volume percent):

A '1 percent ethylene glycol in liquid ammonia;

B. 2 percent ethylene glycol in liquid ammonia;

C. 3 percent ethylene glycol in liquid ammonia;

D. 10 percent ethylene glycol in liquid ammonia.

I In each case the ethylene glycol and the liquid ammonia appear to becompletely miscible with each other and no separation into layers isobserved.

Prepare dyebaths by dissolving 2 grams of Direct Red dye in ml. portionsof each of solutions A D.

Saturate samples of the fabrics in the dyebaths for about 20 seconds.Remove the samples from the dyebaths and dry the fabrics at 20C toremove excess solvent before fmal drying at C for about 2 minutes. Rinseand wash with detergent as before. Iron dry.

Results By comparing swatches with those obtained in Example I, one seesthat the dyeings made with solutions containing ethylene glycol haveabout the same hand and unlevelness as dyeings made from liquid ammoniaonly.

EXAMPLE v percent solution of ethanol in ammonia is prepared by' slowlyadding liquid anhydrous ammonia (42C) to 100 ml. anhydrous ethanol (0C)to make 1,000 m1. solution. The resulting solution is observed to becolorless. No separation of alcohol and ammonia is observed. Temperatureof solution 40C.

saturated in the dyebath for seconds and then drained and air dried at20C to remove excess ammonia. Final drying is at 135 140C for severalminutes. Finally, the fabrics are washed and ironed dry as before.

From an anhydrous ammonia dyebath and from anhydrous ammonia-methanolmixture, Disperse Blue 7 dyes acetate, triacetate, and silk in darkshades. Medium shades are obtained for nylon and viscose; dacrons,cottons, and rayons are not lightly colored. Unleveled dy'eings areobserved on many of thefabrics dyed from liquid ammonia solution.Dyeings from the ammonia-alcohol mixture is observed to be substantiallylevel and has improved hand as compared to dyeings from liquid ammoniaonly.

EXAMPLE Vl Dye: Napthol AS Supra (C.l. Azoic Coupling Component 2)(General Aniline and Film Corp.) Fast Scarlet Salt GGN (C.I. Azoic DiazoComponent 3) (General Aniline and Film Corp.) Naphthol dyeing requires,two' components, the naphthol dye and the developer, to obtaincoloring. v

The Color Index describes the Azoic Coupling Component 2 (CI. No. 27505)as 3-hydroxy-2- naphthanilide. It is sparingly soluble in alcohol andinsoluble in water. The Azoic Diazo Component 3 bears the Colour indexNo. 37010. i

1 Anhydrous ammonia application Dyeing from a completely anhydrousammonia system could not be done because the developer was insoluble inthe ammonia. However, dyeing was achieved in a two-step process in whichthe naphthol is dissolved in anhydrous ammonia and the developer in anaqueous solution.

Naphthol AS (.2 grns.) was dissolved in anhydrous ammonia (280 ml.). Thefabrics l4.0 gms. total) were saturated in solution and then allowed .todry at room temperature. Then the fabrics were. treated in the developersolution and finished as previously described.

. AnhydrousAmmonia Alcohol Application 10 percent solution ofisopropanol in ammonia is prepared following the procedure of Example 1.Dyeing is then achieved in a two-step process in which the napthol isdissolved in anhydrous ammonia-alcohol mixture, and the developer in anaqueous solution.

Naphthol AS (4.4 gms.) is dissolved in anhydrous ammonia-alcohol mixture(300 ml.). The fabrics 14.7 gms. total) are saturated in solution andthen allowed to dry at room temperature. Then the fabrics are treatedinthe developer solution and finished as earlier described. I

Using anhydrous ammonia as the solvent for one dye component and waterfor the other,'intense dyeings of cotton and silk are obtained andparticularly brilliant dyeing of myrrh. Triacetate is not dyed by thistechnique. Unleveled dyeings can be observed however on many of thefabrics dyed from liquid ammonia solution. Dyeings from ammonia-alcoholmixture will be somewhat less deep in shade but substantially level.Hand is to be improved from dyeings with ammonia-alcohol mixture ascompared with dyeings from ammonia only,

particularly for silk and rayon.

EXAMPLE vn Dye: Procion Brilliant Blue MRS (lCl) (C.l. Reactive Blue 4)This dye is identified in the Reactive Dye Chart in I Textile World,August 1964 as having the following structure:

Anhydrous Ammonia Application Prepare dyebath with 3.6 gms. of dye in240 ml. of anhydrous ammonia. Saturate the fabrics l2.l gms. total) inthe dyebath for 20 seconds. Remove fabrics from dyebath, dry off theexcess ammonia at 20C before final drying at C for about 1 minute.Rinse, and iron as before.

Anhydrous ammonia-alcohol mixture application 10 percent solution ofisopropanolin ammonia is prepared following the procedure of Example 1.Prepare dyebath from dye and ammonia-alcohol mixture. Saturate thefabrics (12.4 gms. total) in the dyebath for 20 seconds. Remove fabricsfrom dyebath, dry off the excess ammonia and alcohol at 20C before finaldrying at 120C for about one minute. Rinse and iron as before.

Results With both anhydrous ammonia and with anhydrous ammonia-alcoholsolution, deep dyeing of acetate, triacetate, and silk is obtained.Cottons and rayons are lightly dyed.

Levelness of dyeings made from the ammoniaalcohol mixture will appearsuperior'to levelness of dyeing from ammonia only. Hand improves bydyeing from ammonia-alcohol mixture as contrasted with ammonia only.

EXAMPLE Vlll Dye: Dykolite Brilliant Orange 36 (Southern DyestuffCompany) (Sulfur Dye) No Color Index information is available for thisdyestuff. The manufacturer describes it as a thiocondensate dye forcellulosic fibers. It is prereduced and is supplied as a powder solublein water.

Dykolite Brilliant Orange 30 has the following structure according tothe article Dykolite Dyestuffs for Cellulosic Fibers, Weston andGriffith, Textile Chemist and Colorists, 1, No. 22, pp. 67-82, in oneisomeric form:

Anhydrous ammonia application One-step: To simplify the dyeing process,the dyestuff and fixative are placed in the same bath.

The dyebath is prepared by dissolving 4.7 gms. of dye and 1.2 gms. ofDykoset F-4O (the insolubilizing agent for the dye) in about 315 ml. ofanhydrous ammonia to make a 1.5 percent solution of dye. All fabrics(15.6 gms. total) are saturated for about 20 seconds in the dyebath. Airdry the ammonia from the fabrics at 20C. Briefly wash the fabrics inwarm water and iron dry.

Anhydrous ammonia application Two step: In

' order to see if better coloring of fabric could be obtained from twostep processing, dye is placed in one bath of anhydrous ammonia, andinsolubilizer in another, and the fabrics are treated sequentially ineach.

The dyebath is prepared by dissolving 3.8 gms. of the dye in 248 ml. ofanhydrous ammonia (1.5 percent solution of dye), and the insolubilizingbath by dissolving 1.0 gm. of Dykoset F-40 in 248 ml. of anhydrousammonia. A total of 12.4 gms. of fabric is first saturated in thedyebath for seconds. The excess ammmonia is allowed to evaporate in airand then the fabrics are saturated for a few seconds in theinsolubilizing bath. Excess ammonia is evaporated in air at about 20C,followed by a quick oven dry at l35-l40C. The fabrics are rinsed andwashed as before and then ironed dry.

Anhydrous ammonia-alcohol application Prepare 10 percent mixture ofisopropanol is ammonia as before. Prepare dyebath with 3.6 gms. of dyein 250 ml. of ammonia-alcohol solution. The dye does not appearcompletely soluble. Saturate the fabrics (12.2 gms. total) in thedyebath for 20 seconds. Dry off the excess ammonia-alcohol at 20C beforefinal drying at 120C for about 1 minute. Wash and iron as before.

Results Application of dyestuff from anhydrous ammonia and fromanhydrous ammonia-alcohol mixture, either as a one step or two stepprocess, produces similar results whereby intense color is imparted toacetate, triacetateand silk. Cottons and rayons are lightly colored.Color will not be removed in dry cleaning.

Dyeings with anhydrous ammonia will be somewhat unleveled, particularlydyeings of the acetates and silk and the fiber felt coarse. Dyeing fromthe ammoniaalcohol mixture will be observed to be substantially leveland provide better hand.

EXAMPLE IX The purpose of this example is to show how depth of shadevaries with concentration of dye in anhydrous ammonia-alcohol mixture asit does from an ordinary ammonia dyebath. Direct Blue 67 (Pyrazol FastBrilliant Blue A) is used as the dye for this study. The followingdyebaths are prepared (percent in vol. percent).

1 gm. dye in 300 ml. 10 percent isopropanol in liquid ammonia 2 gms. dyein 300 ml. 10 percent isopropanol in liquid ammonia 4 gms. dye in 300ml. 10 percent isopropanol in liquid ammonia Each fabric to be dyed issaturated for 20 seconds in I the dyebath. The fabrics are dried in airat 20C to remove excess ammonia and isopropanol, and finally EXAMPLE XThe purpose of this example is to show how depth of shade varies withlength of time in the dyebath. Direct Blue 67 (Pyrazole Fast BrilliantBlue A) again is selected as the dye for this study. For each timeinterval, a'dyebath is prepared with 1 gram of dye in 300 ml. of 10percent isopropanol in anhydrous ammonia. Fabric is saturated in thedyebaths for the following times: 2 seconds, 20 seconds, 1 minute and 5minutes. Excess ammonia and alcohol are evaporated from fabrics at 20Cbefore oven drying for 2 minutes at C. The fabrics are then washed inhot waterand ironed dry.

Results After 20 seconds, depth of shade does not appear to increasewith increased time in the dyebath. Fabric treated for only 1 secondappears lighter in shade than fabric treated 20 seconds. Therefore, dyepickup on the fiber seems to occur between 1 and 20 seconds as it doesin dyeing from an alcohol free ammonia dye bath.

As'appears clearly from the foregoing, dyeing from a liquid ammoniadyebath which contains an aliphatic lower alcohol offers all of theadvantagesof a novel rapid method of dyeing at low temperatures achievedby the Tratnyek process with the further advantages improved levelnessand hand.

Since certain changes may be made in the above systems without departingfrom the scope of the invention herein involved, it is intended that allmatter contained in the above description shall be interpreted in anillustrative and not in a limiting sense.

What is claimed is:

1. A dyebath comprising in combination: a

a body of liquid ammonia having a monohydroxy lower alkyl alcoholdissolved therein, and

a dyestuff soluble in liquid ammonia, dissolved in said body.

2. A dyebath asdefined in claim 1 wherein said alcohol is selected fromthe group consisting of methanol, ethanol, n-propanol and isopropanol.

3. A dyebath as defined in claim 1 wherein said dye stuff is selectedfrom the group consisting of direct, disperse, naphthol, reactive andsulfur dyes.

4. A dyebath as defined in claim 1 wherein said alcohol is isopropanol.

5. A dyebath as defined in claim 1 wherein said alcoho] is n-propanol.

6. A dyebath as defined in claim 1 wherein said alcohol is ethanol.

7. A dyestuff as defined in claim 1 wherein said alcohol is methanol.

8. In a method of dyeing organic materials by applying to said materialsa dyebath of liquid ammonia having a dyestuff dissolved therein, theimprovement comprising adding a mono-hydroxy lower alkyl alcohol to saiddyebath.

9. In a method as defined in claim 8 wherein said mono-hydroxy loweralkyl alcohol is selected from the stuff is selected from the groupconsisting of direct, disperse, naphthol, reactive and sulfur dyes.

14. Method as defined in claim 11 wherein said dyestuff is direct dye.

15. Method as defined in claim 11 wherein said dyestuff is a dispersedye.

16. Method as defined in claim 11 wherein said dyestuff is a naphtholdye.

17. Method as defined in claim 11 wherein said dyestuff is a reactivedye.

18. Method as defined in claim 11 wherein said dyestuff is a sulfur dye.

2. A dyebath as defined in claim 1 wherein said alcohol is selected fromthe group consisting of methanol, ethanol, n-propanol and isopropanol.3. A dyebath as defined in claim 1 wherein said dyestuff is selectedfrom the group consisting of direct, disperse, naphthol, reactive andsulfur dyes.
 4. A dyebath as defined in claim 1 wherein said alcohol isisopropanol.
 5. A dyebath as defined in claim 1 wherein said alcohol isn-propanol.
 6. A dyebath as defined in claim 1 wherein said alcohol isethanol.
 7. A dyestuff as defined in claim 1 wherein said alcohol ismethanol.
 8. In a method of dyeing organic materials by applying to saidmaterials a dyebath of liquid ammonia having a dyestuff dissolvedtherein, the improvement comprising adding a mono-hydroxy lower alkylalcohol to said dyebath.
 9. In a method as defined in claim 8 whereinsaid mono-hydroxy lower alkyl alcohol is selected from the groupconsisting of methanol, ethanol, n-propanol and isopropanol.
 10. In amethod as defined in claim 8 wherein said mono-hydroxy lower alkylalcohol is isopropanol.
 11. A method of dyeing organic materials from adyebath comprising the steps of dissolving a dyestuff in a solvent ofliquid ammonia to form said dyebath and adding thereto a mono-hydroxylower alkyl alcohol.
 12. Method as defined in claim 11 wherein saidmono-hydroxy lower alkyl alcohol is admixed with said ammonia prior todissolving said dyestuff in said ammonia.
 13. Method as defined in claim11 wherein said dyestuff is selected from the group consisting ofdirect, disperse, naphthol, reactive and sulfur dyes.
 14. Method asdefined in claim 11 wherein said dyestuff is direct dye.
 15. Method asdefined in claim 11 wherein said dyestuff is a disperse dye.
 16. Methodas defined in claim 11 wherein said dyestuff is a naphthol dye. 17.Method as defined in claim 11 wherein said dyestuff is a reactive dye.18. Method as defined in claim 11 wherein said dyestuff is a sulfur dye.